:root {
    --bg-body: #0a192f;
    --bg-card: #112240;
    --text-main: #ccd6f6;
    --text-muted: #8892b0;
    --accent: #00ff88;
    --border: #233554;
    --font-main: 'Segoe UI', sans-serif;
    --btn-text: #0a192f;
}

[data-theme="light"] {
    --bg-body: #ffffff;
    --bg-card: #f8f9fa;
    --text-main: #333333;
    --text-muted: #555555;
    --accent: #007bff;
    --border: #e0e0e0;
    --font-main: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --btn-text: #ffffff;
}

[data-theme="christmas"] {
    --bg-body: #fff5e6;
    --bg-card: #ffffff;
    --text-main: #8b0000;
    --text-muted: #165b33;
    --accent: #d42426;
    --border: #e6b800;
    --btn-text: #ffffff;
    background-image: radial-gradient(#e6b800 1.5px, transparent 1.5px), radial-gradient(#d42426 1.5px, transparent 1.5px);
    background-size: 35px 35px;
    background-position: 0 0, 17px 17px;
}

[data-theme="dark"] {
    --bg-body: #121212;
    --bg-card: #1e1e1e;
    --text-main: #e0e0e0;
    --text-muted: #a0a0a0;
    --accent: #bb86fc;
    --border: #333333;
    --btn-text: #000000;
}

[data-theme="hacker"] {
    --bg-body: #000000;
    --bg-card: #0d0d0d;
    --text-main: #00ff00;
    --text-muted: #00cc00;
    --accent: #00ff00;
    --border: #004400;
    --font-main: 'Courier New', Courier, monospace;
    --btn-text: #000000;
}
    
    [data-theme="easter-spring"] {
    --bg-body: #fdf0d7;  
    --bg-card: #ffffff;  
    --text-main: #4a4a4a;
    --text-muted: #6b7280; 
    --accent: #165b33;   
    --border: #c5ebd5;   
    --btn-text: #ffffff;
    --font-main: 'Segoe UI', sans-serif;
}

    [data-theme="easter-spring"] h1, 
    [data-theme="easter-spring"] .section-title,
    [data-theme="easter-spring"] h2 {
    font-family: 'Inter', sans-serif !important;
    text-transform: capitalize;
}    
    

* { box-sizing: border-box; margin: 0; padding: 0; transition: background 0.3s, color 0.3s, border 0.3s, box-shadow 0.3s; }

body {
    background-color: var(--bg-body);
    color: var(--text-main);
    font-family: var(--font-main);
    line-height: 1.6;
    scroll-behavior: smooth;
    position: relative;
    min-height: 100vh;
    -webkit-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

a { text-decoration: none; color: var(--accent); }
a:hover { text-decoration: underline; }
ul { list-style: none; }

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 5%;
    background-color: var(--bg-card);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.hamburger {
    display: none;
    cursor: pointer;
}
.bar {
    display: block;
    width: 25px;
    height: 3px;
    margin: 5px auto;
    transition: all 0.3s ease-in-out;
    background-color: var(--text-main);
}

@keyframes type-and-wait-cycle {
    0% { width: 0; }
    30% { width: 8ch; }
    95% { width: 8ch; }
    100% { width: 0; }
}
@keyframes blink-caret {
    from, to { border-color: transparent }
    50% { border-color: var(--accent); }
}

.logo {
    font-size: 1.2rem;
    font-weight: bold;
    color: var(--accent);
    font-family: 'Courier New', Courier, monospace;
    display: inline-block;
    overflow: hidden;
    white-space: nowrap;
    border-right: 3px solid var(--accent);
    width: 0;
    padding-right: 3px;
    animation: type-and-wait-cycle 7s linear infinite, blink-caret .75s step-end infinite;
}

nav ul { display: flex; gap: 15px; align-items: center; }
nav a { color: var(--text-main); font-weight: 500; font-size: 0.9rem; }
nav a:hover { color: var(--accent); text-decoration: none; }

select#theme-selector {
    padding: 5px 10px;
    border-radius: 5px;
    border: 1px solid var(--accent);
    background-color: var(--bg-body);
    color: var(--text-main);
    font-family: var(--font-main);
    cursor: pointer;
}
select#theme-selector option[value="christmas"] { background-color: #d42426; color: white; }

.hero {
    min-height: 95vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 20px;
    border-bottom: 1px solid var(--border);
    position: relative;
    z-index: 1;
}

.profile-wrapper {
    position: relative;
    width: 160px;
    height: 160px;
    margin-bottom: 25px;
}

.profile-pic {
    width: 100%;
    height: 100%;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--accent);
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
    position: relative;
    z-index: 2;
}

[data-theme="christmas"] .profile-wrapper::before {
    content: "";
    position: absolute;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 200 100'%3E%3Cpath fill='none' stroke='%23e6b800' stroke-width='2' d='M0,20 Q50,60 100,20 T200,20'/%3E%3Ccircle fill='%23d42426' cx='25' cy='35' r='6'/%3E%3Ccircle fill='%23165b33' cx='75' cy='35' r='6'/%3E%3Ccircle fill='%23e6b800' cx='125' cy='35' r='6'/%3E%3Ccircle fill='%23d42426' cx='175' cy='35' r='6'/%3E%3C/svg%3E");
    background-size: contain;
    background-repeat: no-repeat;
    width: 180px;
    height: 80px;
    top: -30px;
    left: -10px;
    z-index: 3;
}

.hero h1 { font-size: 2.5rem; margin-bottom: 10px; }
.hero h2 { font-size: 1.2rem; color: var(--accent); margin-bottom: 20px; font-weight: normal;}
.hero p { font-size: 1.1rem; color: var(--text-muted); margin-bottom: 30px; max-width: 700px; }

.social-links {
    display: flex;
    gap: 15px;
    margin-bottom: 30px;
    flex-wrap: wrap;
    justify-content: center;
    position: relative;
    z-index: 10;
}

.btn {
    display: inline-block;
    padding: 10px 20px;
    background-color: var(--accent);
    color: var(--btn-text);
    border-radius: 5px;
    font-weight: bold;
    font-size: 0.9rem;
    border: 1px solid var(--accent);
    cursor: pointer;
    text-decoration: none !important;
}

.btn-outline { background-color: transparent; color: var(--text-main); border: 1px solid var(--text-main); }
.btn:hover, .btn-outline:hover { opacity: 0.8; }

.container { padding: 60px 10%; border-bottom: 1px solid var(--border); }
.section-title { font-size: 1.8rem; margin-bottom: 40px; text-align: center; color: var(--accent); text-transform: uppercase; letter-spacing: 1px; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 20px; }
.card {
    background-color: var(--bg-card);
    padding: 25px;
    border-radius: 8px;
    border: 1px solid var(--border);
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    display: flex;
    flex-direction: column;
}
.card h3 { margin-bottom: 15px; color: var(--text-main); font-size: 1.2rem; border-bottom: 1px solid var(--border); padding-bottom: 10px; }
.card p, .card li { color: var(--text-muted); font-size: 0.95rem; margin-bottom: 10px; }
.card ul { padding-left: 20px; list-style-type: square; }
footer { text-align: center; padding: 30px; background-color: var(--bg-card); color: var(--text-muted); font-size: 0.9rem; }

[data-theme="hacker"] .hero h1::after { content: "_"; animation: blink 1s infinite; }
@keyframes blink { 50% { opacity: 0; } }

.click-decoration {
    position: absolute;
    pointer-events: none;
    font-size: 1.5rem;
    animation: vanish 1.5s forwards;
    z-index: 9999;
}

@keyframes vanish {
    0% { opacity: 1; transform: translateY(0); }
    100% { opacity: 0; transform: translateY(50px) rotate(20deg); }
}

#particles-js {
    position: fixed;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    z-index: 0;
    background-color: transparent;
    pointer-events: none;
}

@keyframes systemBoot {
    0% { opacity: 0; transform: translateY(50px); filter: blur(5px); }
    100% { opacity: 1; transform: translateY(0); filter: blur(0); }
}
.hero-text { opacity: 0; animation: systemBoot 1s ease-out forwards; animation-delay: 0.2s; }
.hero-image { opacity: 0; animation: systemBoot 1s ease-out forwards; animation-delay: 0.5s; }
.section-title { 
    font-family: 'Orbitron', sans-serif; 
    font-size: 1.8rem; 
    margin-bottom: 40px; 
    text-align: center; 
    color: var(--accent); 
    text-transform: uppercase; 
    letter-spacing: 2px;
    font-weight: 700;    
    
    opacity: 0;
    animation: systemBoot 0.8s ease-out forwards;
    animation-delay: 0.3s;
}
.card { opacity: 0; animation: systemBoot 0.8s ease-out forwards; animation-delay: 0.6s; }
.btn { opacity: 0; animation: systemBoot 0.5s ease-out forwards; animation-delay: 0.8s; }

@media screen and (max-width: 768px) {
    .hamburger {
        display: block;
        position: absolute;
        top: 20px;
        right: 20px;
        z-index: 1001; 
    }

    nav ul {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--bg-card);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.05);
        gap: 0;
        z-index: 1000;
        padding-bottom: 20px;
    }
   
    nav ul.active {
        left: 0;
    }

    nav ul li { margin: 15px 0; }

    .hamburger.active .bar:nth-child(1) { transform: translateY(8px) rotate(45deg); }
    .hamburger.active .bar:nth-child(2) { opacity: 0; }
    .hamburger.active .bar:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }

    header { 
        flex-direction: column !important; 
        height: auto !important; 
        padding: 20px 0;
        align-items: center;
    }
    .logo { 
        display: block !important; 
        margin-bottom: 0; 
        align-self: flex-start; 
        margin-left: 20px;
    }

    nav a {
        display: block;
        padding: 10px 20px;
        width: 100%;
    }
    
    #theme-selector {
        margin-top: 10px;
    }

    .hero-image { order: -1; margin-bottom: 30px; margin-top: 0 !important; animation-delay: 0.1s; }
    .hero-text { padding-right: 0 !important; text-align: center; animation-delay: 0.3s; }
    .hero-text div[style*="display: flex"] { justify-content: center; }
    .social-links { justify-content: center; }
}

.tech-stack {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-bottom: 15px;
}

.tech-tag {
    font-size: 0.75rem;
    font-family: 'Orbitron', sans-serif;
    color: var(--accent);
    background: rgba(0, 0, 0, 0.2); 
    border: 1px solid var(--accent);
    padding: 5px 12px;
    border-radius: 20px; 
    transition: all 0.3s ease;
}

.tech-tag:hover {
    background: var(--accent);
    color: var(--bg-card); 
    transform: translateY(-2px);
}

.terminal-window {
    background: #0d1117;
    border: 1px solid #30363d;
    border-radius: 6px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
    overflow: hidden;
    margin-top: 20px;
    font-family: 'Courier New', monospace;
}

.terminal-header {
    background: #161b22;
    padding: 10px 15px;
    display: flex;
    align-items: center;
    border-bottom: 1px solid #30363d;
}

.terminal-dots {
    display: flex;
    gap: 6px;
    margin-right: 15px;
}

.terminal-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.red-dot { background: #ff5f56; }
.yellow-dot { background: #ffbd2e; }
.green-dot { background: #27c93f; }

.terminal-title {
    color: #8b949e;
    font-size: 0.8rem;
}

.terminal-body {
    padding: 20px;
    color: #c9d1d9;
    font-size: 0.9rem;
}

.cmd { color: var(--accent); }
.output { color: #8b949e; display: block; margin-bottom: 10px; }

.floating-book-btn {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background: var(--bg-card);
    border: 2px solid var(--accent);
    color: var(--text-main);
    padding: 12px 25px;
    border-radius: 50px;
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    font-family: 'Orbitron', sans-serif;
    font-weight: bold;
    font-size: 0.9rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
    z-index: 9999;
    transition: all 0.3s ease;
    animation: float 3s ease-in-out infinite;
}

.floating-book-btn:hover {
    transform: translateY(-5px) scale(1.05);
    background: var(--accent);
    color: var(--bg-body);
    box-shadow: 0 0 20px var(--accent);
}

.floating-book-btn .badge {
    background: #ff0000;
    color: white;
    font-size: 0.6rem;
    padding: 2px 6px;
    border-radius: 4px;
    position: absolute;
    top: -10px;
    right: -5px;
    font-weight: bold;
}

@keyframes float {
    0% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
    100% { transform: translateY(0px); }
}

@media screen and (max-width: 768px) {
    .floating-book-btn {
        bottom: 20px;
        right: 20px;
        padding: 10px 20px;
        font-size: 0.8rem;
    }
}

.book-card {
    background: linear-gradient(135deg, rgba(10, 25, 47, 0.95), rgba(0, 255, 136, 0.1));
    border: 1px solid var(--accent);
    border-radius: 20px;
    padding: 60px;
    min-height: 400px; 
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 50px; 
    box-shadow: 0 20px 50px rgba(0, 255, 136, 0.15);
    position: relative;
    overflow: visible; 
    margin-top: 80px;
}

.book-info {
    flex: 1.2; 
    z-index: 2;
}

.book-info h2 {
    font-family: 'Orbitron', sans-serif;
    color: var(--accent);
    margin-bottom: 20px;
    font-size: 2.2rem; 
    text-transform: uppercase;
    letter-spacing: 1px;
}

.book-info p {
    color: var(--text-main);
    margin-bottom: 35px;
    font-size: 1.1rem; 
    line-height: 1.8;
}

.cta-btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: var(--accent);
    color: var(--bg-body);
    padding: 15px 35px;
    border-radius: 5px;
    font-weight: bold;
    font-family: 'Orbitron', sans-serif;
    text-decoration: none;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.cta-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 0 20px var(--accent);
}

.book-visual {
    flex: 1;
    display: flex;
    justify-content: center;
    perspective: 1000px;
    z-index: 2;
}

.book-visual img {
    max-width: 350px;
    width: 100%;
    filter: drop-shadow(0 30px 40px rgba(0, 0, 0, 0.6));
    animation: float-book 6s ease-in-out infinite;
    transform-style: preserve-3d;
}

@keyframes float-book {
    0%, 100% { transform: translateY(0px) rotateY(-5deg); }
    50% { transform: translateY(-25px) rotateY(5deg); }
}

@media screen and (max-width: 900px) {
    .book-card {
        flex-direction: column-reverse;
        text-align: center;
        padding: 40px 20px;
        gap: 30px;
    }
    
    .book-visual img {
        max-width: 280px; 
        margin-bottom: 20px;
    }

    .book-info h2 {
        font-size: 1.5rem;
    }
}